Warning-signal for electric-motor controllers.



No. 824,223. PATENTED JUNE 26, 1906.

. W; H. WARREN. WARNING SIGNAL FOR ELECTRIC MOTOR CONTROLLERS.

' APPLICATION FILED OCT. 25. 1905.

UhllTElli STATlf-iti PATENT UhlBl CES WILLiAh l H. WARREN, OF BROOKLYN, NEW YORK, ASSIGNOR TO W ESTE RN ELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A COR- PORATION OF lLLlNOlS.

Specification of Letters Patent.

Patented June 26, 1906.

Application filed October 25, 1905. Serial No. 284,290.

To ctZl whom it may concern:

Be it known. that 1, WILLIAM H. WARREN, a subject of the King of Great Britain, residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Warning- Signals for Electric-Motor Controllers, of which the following is a full, clear, concise, and exact description.

My invention relates to a motor-controller, and has for its object the provision of a signal for indicating safe and unsafe position of the controlleredrum during its operation.

In some systems for operating motors the insertion of resistance is required in the armature-circuit when the controller is moved to starting position. It is undesirable that the controller long remain at such position, for the reason that the resistance may interfere with the s eed regulation or maybe damaged by over resting. Also if the drum be held in a position intermediate two notches While cutting resistance in or out of the fieldcircuit the contact-fingers will rest in between instead of on the circuit contaot-bloc rs of the drum.

For the purpose of notifying the operator when the controller is in any of the positions in which it should not be allowed to remain I have devised a signal, placed in a conspicuous position near the operator, and a series of contacts on the main drum arranged to close the circuit of the signal and cause it to be 0 erated at each intermediate position of t e controller and also when the armature resistance is in use. Thus whenever the controller is in improper position the attention of the operator will be called to that fact.

My invention is particularly adapted for use in connection with a motor-controller such as is shown, for example, in patent to Walter J. VVarder, Jr., No. 790,541, dated May 1905.

1 will describe my invention more particularly by reference to the accompanying drawing, which is a diagrammatic view showing the drum developed in order to clearly illustrate the arrangement of circuits.

The iron drum, as shown, consists of insulated sections and is of course mounted, as usual, on a shaft carrying the controller-handi; The operation. of the drum is well known and need not be described in detail.-

On the drum are the contact-blocks a b c d e, adapted to contact with the fingers a b c d e,res ectively, upon the rotationof the drum.

W on the switch is closed to connect the motor with the mains, the circuit from the terminals will be closed through the conductor w, the shunt resistance R, the shunt field-magnet coils A, and conductor 3 When the controller is moved forward into position 1, the drum is rotated, so that fingers b c e f 9 7c I -contact with the blocks b c e f g k 1', respectively. A circuit is then closed through the line it, contacts I) and c, armature resist' ance R, armature-motor M, contacts e and f, and line 2. The resistance B Is short-circuited through the finger g, contact-blocks g and 7c, and finger lc. In this position the current flows through the armature resist ance, and it is undesirable, for reasons already stated, that the controller long remain in such osition. I therefore provide a signal, here s own as a lamp L, to Warn the (zperator. The lamp has one terminal secure to the finger Z and the other to finger f, connected to inc 2. When the control er is in position 1, the finger Z rests on the block Z and. the circuit is closed through the lamp, thereby lighting it to attract the operators attention.

When the controller is moved to the point ,2, the resistance R is cut out by the finger (Z contacting with the block d, the controller is then in a safe position, the circuit containing the lamp is open, and the lam extinguished. By movin the controllerever to point 3 a portion of 516 shunt resistance R is included in the shunt-circuit, and by moving it to points 4 and 5 additional resistance is cut in. When in any of the positions 2 3 4 5, the contact-fingers rest on the blocks and the motor-controller is in proper running position. Should the controller be placed in a position intermediate any of the two points, thereby causing the contact-fingers to rest between the contact-blocks, the operator's attention is called to this unsafe position of the controller by the lamp being lighted. This is due to the fact that the fin er 1 in an one of said improper positions of t e contro ler contacts with one of a series of blocks Z Z 1 l situated on the drum between the points 1, 2, 3, 4, and 5, and the circuit containing the signal is thereb closed. In moving the controller-lever rem point 5 to point 6 the con- 3O signal may be used instead of a; lamp.

tact-fingers a b c d e f do not rest on contact points on the drum, thereby opening the circuit through the motor-armature, and the motor will tend to stop. In this intermediate position, however, the contact-point Z rests on block Z and the Warning-signal is operated. When the controller-lever reaches the point 6, the fingers a b d 0 contact with theblocks a b d e respectively. The block a" is mounted on a separately-insulated section of the drum and is electrically connected with block e In this position a circuit is closed from the mains through blocks 12 and d motor-armature M, blocks e and a," to the conductor y. The controller is in a safe position, and the warning-signal is not operated. If, however, the controller is moved forward to regulate the resistance R in the shunt-field at every sition intermediate the main coirtact-bloc s, the finger Z will rest on a corresponding auxiliary contact-block and the warning-signal operated.

While I have described the o eration of the device only while the control er lever is moved forward, it is obvious that in the reverse position of the lever the signal will be operated in a similar manner.

Though I have shown a lamp in the draw-" ing, I do .not limit myself to the use of any particular signal device. Any other suitable What I claim is- 1. The combination with the. switching mechanism of a motor-controller, of a circuit including a signal for indicating safe and unsafe positions of the controller mechanism,

and additional switching mechanism, which moves with each movement of the controller, to control the signal-circuit.

2. In acontroller for'electric motors, the' combination'with a'I'notor-circuit, of a normally open circuit including a signal, a contact-finger to which one terminal of the sig nal is connected, and a series of contactblocks on the controller-drum, adapted to engage with said finger when the controller is in improper running positions, and thereby to close the signal-circuit. v

3. In a controller for electric motors, the.

combination with the motor-circuit, of anormally open shunt-circuit including a signal, a 1

series of contact blocks on the controller drum located in positions intermediate the proper running positions of the controller, a

- finger connected. to one terminal of the signal and adapted to engage said contact-blocks to close the signal-circuit when the controll'e mechanism is in an unsafe position. I

4; In a controller for electric motors, the combination with a controller-drum having a series of main contact-blocks thereon, of a series of fingers adapted to engage said blocks for controlling the motor circuit, a normally open shunt-circuit including a signal, an auxiliary contact-finger to which one terminal of the signal is connected, and a series of auxiliary contact-blocks onthe controller-drum so located as to engage the aurn'liary finger when the controller mechanism is in unsafe position and thereby to close the signal-circuit.

In witness whereof I hereunto subscribe my I name this 4th day of October, D. 1905.

WILLIAM H. WARREN. Witnesses: I

'GEORGE "S. WEsToN, 2d. EDWARD P. HOPKINS. 

